1. Field of Invention
This invention relates to a device for driving a roof-hatch for opening and closing a lid of the roof-hatch which is provided in a roof of a vehicle.
2. Description of the Prior Art
Heretofore, there has been used a device for driving a roof-hatch as shown in FIG. 7.
The device for driving the roof-hatch 100 shown in FIG. 7 has a knob 102 on the room side of a casing 101, which actuates a roof-hatch lid 104 forming a part of a roof 103 by tilting-up or tilting-down by manual turning of the knob 102. In the figure, numeral 105 is the first gear formed in a body with said knob 102, numeral 106 is a shaft supporting the knob 102 and said first gear 105 rotatably, numeral 107 is an intermediate gear having a gear part 107a engaged with the first gear 105 and a worm part 107b in a body, numeral 108 is an output shaft having a gear part 108a engaged with the worm part 107b of said intermediate gear 107 and a gear part 108b similar to said gear part 108a in shape, which connects the gear part 108a and 108b with a connecting shaft 108c, and numeral 109 is a rack attached to the roof rotatably to the roof-hatch lid 104 by a bracket 104a and engaged with said gear part 108b provided to the output shaft 108.
In the device for driving the roof-hatch 100 having the above mentioned structure, when the knob 102 rotates by manual turning, the rotation of the knob 102 is transmitted to the gear part 107 through the first gear 105, and so said intermediate gear 107 rotates. And the output shaft 108 rotates by transmitting the rotation to the gear part 108a provided to the output shaft 108 from the worm part 107b of the intermediate gear 107, so that the rotation of the gear part 108b provided to said output shaft 108 drives the rack 109 and operates the roof-hatch lid 104 into tilting-up or tilting-down. When the roof-hatch lid 104 reaches the top point of the tilting-up position, the rack 109 is disengaged and released from the gear part 108b of the output shaft 108 by unlocking the rack-lock system (not shown), and so said roof-hatch lid 104 is enabled to be detached from the roof 103.
In the aforementioned device for driving the roof-hatch 100, the driving force operating the lid 104 into tilting-up or tilting-down is obtained depending upon the reduction ratio of the knob 102 rotating manually that is the first gear 105 to the gear part 107a of the intermediate gear 107, the reduction ratio of the gear part 107b of the intermediate gear 107 to the gear part 108a of the output shaft 108 and reduction ratio of the gear part 108b of the output shaft 108 to the rack 109. Accordingly, it is necessary to increase said reduction ratios corresponding to the weight of the lid 104 and to toughen the strength of the respective gears. As the result, the device for driving the roof-hatch 100 is unavoidable scaling up the body, it can be an obstacle in the passenger compartment of the vehicle. In addition to above, there is a problem that the troublesome operation of the knob 102 interferes with the safe running of the vehicle, because the device for driving the roof-hatch 100 must be worked by the manual turning of said knob 102 repeatedly.